New block-copolymer thermoassociating matrices for DNA sequencing: Effect of molecular structure on rheology and resolution

A new family of matrices for DNA sequencing by capillary electrophoresis is presented. These matrices combine easy injection with high sieving perform ances, due to thermal switching between a low and a high viscosity state th rough a modest increase in temperature (similar to 20 degreesC). They are c onstructed from a hydrophilic polymer backbone with grafted lower critical solution temperature (LCST) side chains. The comb-like LCST copolymers are characterized in terms of size of the polymer backbone, the size of LCST si de chains and the grafting densities. The dependance of rheological behavio r and electrophoretic performance of these copolymers is correlated with th eir microstructure. Without complete optimization, a resolution of order 0. 5, corresponding to a very reasonable limit for read length with current ba se calling softwares, could be achieved for segments around 800 bases diffe ring by 1 base in less than one hour in a commercial ABI 310 apparatus.